Questions tagged [digital-comparator]
A digital comparator or magnitude comparator is a hardware electronic device that takes as input two numbers in binary and determines whether one number is greater than, less than or equal to the other number. Four-bit examples are the CMOS 4063 and the TTL 7485.
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Voltage Input Biasing on NMOS in CMOS Comparator
As part of my discrete transistor computer project, I want to keep the theme with the clock module. It took a little research, but I think I have some grasp on how OpAmps work. However, I found a ...
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Help to solve 74LS85 comparator
I am working on a 4-bit comparator problem using a 74LS85 chip. I have two 4-bit binary inputs, A and B, and I am trying to determine the output signals (A = B, A > B, A < B) based on the timing ...
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Adding series resistors to IC, increases input impedance?
Does adding series resistors to a comparator / op-amp IC increase input impedance? Is this a right way to do?
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How do I make a gate with only one condition?
I need a simple gate with one condition only but with two ends, if its given 10V it will deliver a square wave from an oscillator I've built, if not then it will deliver a wave from a signal generator,...
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Using a 1-bit input to signal signed vs. unsigned comparison (in CircuitVerse)
Disclaimer, I'm a total electronics/circuit noob so sorry if this is really simple! But I've just built a 4-bit less-than comparator in CircuitVerse (outputs whether A < B), and I want to use a 1-...
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3-to-2 line encoder (or generally 2^(n-1)-to-n) -- not priority, but telling how many inputs are on?
This is not homework (not taking any classes) although it could be homework. I am wondering what is the easiest implementation using a single TTL chip or gates (fewest chip count) to encode the number ...
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Digital Design: Is there an elegant way to put a number in a sorted register file?
Let's say we have a module that has a register file currently inside that can hold 3 numbers. Suppose the three numbers are: 4, 6, 7. 4 is at index 0, 6 is at index 1, and 7 is at index 2. A new ...
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Circuit to detect two sequential pulses
I have a window comparator with two outputs (hi-threshold and low-threshold) that would go high sequentially (few examples shown in the attached image). I want to use to combine these two signals into ...
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Duty cycle detection circuit for square wave
I have two signals coming out of one block. One signal is one period delayed than the other one. Is there any method to detect the duty cycle of these pulses?.
Edit:
Clk is my original signal. Going ...
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Detect a sequence inside a bit stream
I was recently in a discussion with my professor in which he told me that 'absolutely in no way would this design work'. I am hoping I could bounce it off you guys.
The question asked to design (in ...
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Why aren’t the magnitude comparators cascaded the “more efficient” way?
In Practical Electronics for Inventors, Paul shows the following cascading of two \$ 74HC85 \$’s to build an 8-bit magnitude comparator.
Question: Why doesn’t he cascade them in the apparently more ...
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Curious Behavior In Logisim while trying to mimic a halt instruction
I'm in the process of trying to simulate a halt instruction based on some arbitrary value. My circuit design may not follow best practices as I'm disabling the overall or master clock sign with a ...
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Comparing sine wave and triangular for spwm using comparator
i am trying to generate sinusoidal PWM by comparing sine and triangular wave.
First i just tried to compare sine wave with reference voltage in order to check the working of op-amp. I get a problem ...
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Digital Comparator from LSB to MSB using Lookahead
This is homework to be upfront, but I'm really stuck on it and just need some kind of direction. I've been assigned to create a 16-bit lookahead comparator going from LSB to MSB using no more than 4-...
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How to design a combinational circuit that finds the minimum among multiple given numbers?
There are quite a few articles (for example, this) that can be found online discussing the design of a comparator that takes two numbers (say, A and ...
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Comparator on Logisim
Currently working on an elevator circuit. I am using 4-bits to represent the floor that the elevator is on, and I need a way of comparing this value to the floor that the user wants to get to. I am ...
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LT Spice Comparator Question [closed]
Does LT Spice have any way of creating a 4-bit Comparator with outputs A=B, A>B, A
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How do I design a cascade network of 1-bit comparators to determine if two n-bit numbers are equal?
I'm reading through the "Logic Design" chapter in Givone's Digitial Principles and Design and this is one of the problems at the end of the chapter. I read the section on comparators thoroughly, but ...
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Digital Magnitude Comparator: LSb first or MSb first
Most of the comparator designs/algorithms are based on MSb first approach (i.e, starting the comparison from MSb of the two numbers), which seems to be effective approach intuitively.
I was just ...
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IC 7485 truth table
For IC 7485 truth table(given below), why is the the output A>B = 1 and A<B = 1 when you have got the inputs A(3,2,1,0)=B(3,2,1,0) with 0 for all cascading inputs(the last row). What exactly is the ...
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